RegularExpressionValidator.EvaluateIsValid-Methode

Gibt an, ob der Wert im Eingabesteuerelement gültig ist.

Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)

Syntax

'Declaration
Protected Overrides Function EvaluateIsValid As Boolean
'Usage
Dim returnValue As Boolean

returnValue = Me.EvaluateIsValid

protected override bool EvaluateIsValid ()

protected:
virtual bool EvaluateIsValid () override

protected boolean EvaluateIsValid ()

protected override function EvaluateIsValid () : boolean

Rückgabewert

true, wenn der Wert im Eingabesteuerelement gültig ist, andernfalls false.

Beispiel

Im folgenden Codebeispiel wird veranschaulicht, wie die EvaluateIsValid-Methode in einem benutzerdefinierten Serversteuerelement überschrieben wird, sodass es den Wert immer auf einen Ausdruck für eine Übereinstimmung in einem RegularExpressionValidator prüft.

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomRegularExpressionValidatorEvaluateIsValid
        Inherits System.Web.UI.WebControls.RegularExpressionValidator

        Protected Overrides Function EvaluateIsValid() As Boolean

            ' Get the control to validate's validation value
            Dim controlValue As String = GetControlValidationValue(Me.ControlToValidate)

            ' If the value is null or empty, then return true
            If controlValue Is Nothing OrElse controlValue.Trim().Length = 0 Then
                Return True
            Else
                ' Else try running the Regular Expression against the value 
                ' and see if there is a match.
                Try
                    Dim regExpMatch As System.Text.RegularExpressions.Match = System.Text.RegularExpressions.Regex.Match(controlValue, Me.ValidationExpression)
                    Return regExpMatch.Success AndAlso regExpMatch.Index = 0 AndAlso regExpMatch.Length = controlValue.Length
                Catch
                    Return True
                End Try
            End If
        End Function
    End Class
End Namespace

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomRegularExpressionValidatorEvaluateIsValid : System.Web.UI.WebControls.RegularExpressionValidator
  {
    protected override bool EvaluateIsValid()
    {
      // Get the control to validate's validation value
      string controlValue = GetControlValidationValue(this.ControlToValidate);
      
      // If the value is null or empty, then return true
      if (controlValue == null || controlValue.Trim().Length == 0) 
      {
        return true;
      }
      else
      {
        // Else try running the Regular Expression against the value 
        // and see if there is a match.
        try 
        {
          System.Text.RegularExpressions.Match regExpMatch = System.Text.RegularExpressions.Regex.Match(controlValue, this.ValidationExpression);
          return(regExpMatch.Success && regExpMatch.Index == 0 && regExpMatch.Length == controlValue.Length);
        }
        catch 
        {
          return true;
        }
      }
    }
  }
}

package Samples.AspNet.JSL.Controls; 

public class CustomRegularExpressionValidatorEvaluateIsValid
    extends System.Web.UI.WebControls.RegularExpressionValidator
{
    protected boolean EvaluateIsValid()
    {
        // Get the control to validate's validation value
        String controlValue = GetControlValidationValue(this.
            get_ControlToValidate());
        // If the value is null or empty, then return true
        if (controlValue == null || controlValue.Trim().get_Length() == 0) {
            return true;
        }
        else {
            // Else try running the Regular Expression against the value 
            // and see if there is a match.
            try {
                System.Text.RegularExpressions.Match regExpMatch 
                    = System.Text.RegularExpressions.Regex.Match(controlValue,
                    this.get_ValidationExpression());
                return regExpMatch.get_Success() 
                    && regExpMatch.get_Index() == 0 
                    && regExpMatch.get_Length() == controlValue.get_Length();
            }
            catch (System.Exception exp) {
                return true;
            }
        }
    } //EvaluateIsValid
} //CustomRegularExpressionValidatorEvaluateIsValid

Im folgenden Codebeispiel wird veranschaulicht, wie das im vorhergehenden Beispiel definierte CustomRegularExpressionValidatorEvaluateIsValid-Steuerelement auf einer Web Forms-Seite angewendet wird.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom RegularExpressionValidator - EvaluateIsValid - VB.NET Example</title>
    <script runat="server">
      Sub Button1_Click(sender As Object, e As EventArgs)
          If Page.IsValid Then
              Label1.Text="Page is valid."
          Else
              Label1.Text="Page is not valid!"
          End If
      End Sub
    </script>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom RegularExpressionValidator - EvaluateIsValid - VB.NET Example</h3>
       <table bgcolor="#eeeeee" cellpadding="10">
          <tr valign="top">
             <td colspan="3">
                <asp:Label ID="Label1" 
                  Text="Enter a 5 digit zip code" 
                  runat="server"/>
             </td>
          </tr>
 
          <tr>
             <td colspan="3">
                <b>Personal Information</b>
             </td>
          </tr>
          <tr>
             <td align="right">
                Zip Code:
             </td>
             <td>
                <asp:TextBox id="TextBox1" runat="server"/>
             </td>
             <td>
                <aspSample:CustomRegularExpressionValidatorEvaluateIsValid
                  id="Regularexpressionvalidator1" 
                  runat="server"
                  ControlToValidate="TextBox1"
                  ValidationExpression="\d{5}"
                  ErrorMessage="Zip code must be 5 numeric digits"
                  Display="Static"
                  EnableClientScript="False" />
             </td>
          </tr>
          <tr>
             <td></td>
             <td>
                <asp:Button text="Button1" 
                  OnClick="Button1_Click" 
                  runat=server ID="Button1"/>
             </td>
             <td></td>
          </tr>
       </table>

        </form>
    </body>
</HTML>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom RegularExpressionValidator - EvaluateIsValid - C# Example</title>
    <script runat="server">
      void Button1_Click(Object sender, EventArgs e) 
      {
        if (Page.IsValid) 
        {
          Label1.Text = "Page is valid.";
        }
        else 
        {
          Label1.Text = "Page is invalid!";
        }
      }
    </script>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom RegularExpressionValidator - EvaluateIsValid - C# Example</h3>
       <table bgcolor="#eeeeee" cellpadding="10">
          <tr valign="top">
             <td colspan="3">
                <asp:Label ID="Label1" 
                  Text="Enter a 5 digit zip code" 
                  runat="server"/>
             </td>
          </tr>
 
          <tr>
             <td colspan="3">
                <b>Personal Information</b>
             </td>
          </tr>
          <tr>
             <td align="right">
                Zip Code:
             </td>
             <td>
                <asp:TextBox id="TextBox1" runat="server"/>
             </td>
             <td>
                <aspSample:CustomRegularExpressionValidatorEvaluateIsValid
                  id="Regularexpressionvalidator1" 
                  runat="server"
                  ControlToValidate="TextBox1"
                  ValidationExpression="\d{5}"
                  ErrorMessage="Zip code must be 5 numeric digits"
                  Display="Static"
                  EnableClientScript="False" />
             </td>
          </tr>
          <tr>
             <td></td>
             <td>
                <asp:Button text="Button1" 
                  OnClick="Button1_Click" 
                  runat=server ID="Button1"/>
             </td>
             <td></td>
          </tr>
       </table>

        </form>
    </body>
</HTML>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL.Controls" Assembly="Samples.AspNet.JSL" %>
<%@ Page Language="VJ#" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom RegularExpressionValidator - EvaluateIsValid - VJ# Example</title>
    <script runat="server">
        void Button1_Click(Object sender, EventArgs e) 
        {
            if (get_Page().get_IsValid()) {
                Label1.set_Text("Page is valid.");
            }
            else {
                Label1.set_Text("Page is invalid!");
            }
        } //Button1_Click
    </script>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom RegularExpressionValidator - EvaluateIsValid - VJ# Example</h3>
       <table bgcolor="#eeeeee" cellpadding="10">
          <tr valign="top">
             <td colspan="3">
                <asp:Label ID="Label1" 
                  Text="Enter a 5 digit zip code" 
                  runat="server"/>
             </td>
          </tr>
 
          <tr>
             <td colspan="3">
                <b>Personal Information</b>
             </td>
          </tr>
          <tr>
             <td align="right">
                Zip Code:
             </td>
             <td>
                <asp:TextBox id="TextBox1" runat="server"/>
             </td>
             <td>
                <aspSample:CustomRegularExpressionValidatorEvaluateIsValid
                  id="Regularexpressionvalidator1" 
                  runat="server"
                  ControlToValidate="TextBox1"
                  ValidationExpression="\d{5}"
                  ErrorMessage="Zip code must be 5 numeric digits"
                  Display="Static"
                  EnableClientScript="False" />
             </td>
          </tr>
          <tr>
             <td></td>
             <td>
                <asp:Button text="Button1" 
                  OnClick="Button1_Click" 
                  runat=server ID="Button1"/>
             </td>
             <td></td>
          </tr>
       </table>

        </form>
    </body>
</HTML>

Plattformen

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

RegularExpressionValidator-Klasse
RegularExpressionValidator-Member
System.Web.UI.WebControls-Namespace